Technical Field
The present invention relates to a transmission station for feeding locally provided electrical energy and, in particular, electrical energy provided by one or more wind power installations into a grid. The invention further relates to a wind farm comprising one or more such transmission stations.
Description of the Related Art
Wind power installations are increasingly used to provide electrical energy. The rotational movement of the rotors that is produced by wind power is transformed to AC voltage by means of generators, and is then discharged from the wind power installation and ultimately fed into a public utilities network, hereinafter also referred to as grid. For feed-in purposes, the voltage produced by the wind power installation is brought to the required form by means of various controls. This mostly requires the use of inverters and/or rectifiers and of one or more transformers. These intermediate steps are taken either at the wind power installation itself or at corresponding control installations that are external to the wind power installation. If controls that are external to the wind power installation as well as further infrastructure for feed-in purposes should be required, such required controls are accommodated in housings to, on the one hand, offer protection from external influences and, on the other, to protect the environment from damages caused by voltage. Housings that accommodate the connection to the grid are referred to as transmission stations in the industry.
In such transmission stations, control units are provided for to ensure that the voltage delivered to a transmission station is provided such that it can be fed into the grid via a line connection that belongs to the grid. Whether or not this requires voltage direction and/or transformation inside the transmission station depends on the wind power installations used from time to time and possibly on interconnected further stations.
Because of the high voltages and/or currents present at such transmission stations that occasionally collect the electrical energy provided by several wind power installations and process it for feed-in purposes, there is a risk of short-circuits in the control units. In extreme cases, this may lead to the formation of electric arcs inside the control units, which then lead to a gas explosion inside the transmission station that is accompanied by the propagation of a blast wave and heavy smoke formation. This is a major health risk especially for those who are present at the transmission station at the time of formation of an electric arc.
Various arrangements are described in prior art, whose goal it is to remove as quickly as possible the smoke that has formed at such places inside a transmission station, where people might be located. However, general plant safety still needs to be improved at such transmission stations.
Given the ever increasing sale of wind power installations and an increasingly local organization of power generation because of the growing share of regenerative energy, there is, in particular, an additional duty to ensure the improvement of safety at transmission stations in an economically efficient manner.